Interesting roundup from Science Over Everything:
As long as they have existed, bees have been an important and integral part of the Earth’s ecosystem; they help flowering plants reproduce and make it possible for you to enjoy a tasty bowl of Honey Nut Cheerios in the morning. However, scientists have recently observed entire colonies of bees dying off without a clear explanation. Though a world without bees would let you enjoy a picnic free from the fear of being stung, it could have devastating consequences for nearly every land community in the world.
What is happening?
Over the last 10 years or so, scientists in North America and Europe have noticed entire colonies of bees dying off, leaving behind plenty of food, a healthy queen, and a few nurse bees to care for the remaining larvae. Called Colony Collapse Disorder, (CCD), this phenomena has led to the loss of billions of bees. The National Agriculture Statistics Service reported that there were 2.44 million honey-producing colonies in the United States as of February 2008, down from 4.5 million in 1980, and 5.9 million in 1947. The number of hives surviving the winter, a helpful indicator for CCD, showed that 23.1% of hives across the United States did not make it from fall 2014 to spring 2015. While this is down from nearly 30% losses in the 2006-2007, it still represents staggering drop in bee populations, with some areas experienced up 90% of hives dying off over winter.
Do we have an idea why these bees are dying?
No one is really sure why this is happening, but researchers have a few hypotheses. One of the leading explanations is that hives have been stressed due to exposure to pesticides. These poisons, which are meant to kill pests that destroy crops, do not discriminate which insects are affected. Another cause could be that the deforestation across the developed world has drastically reduced available habitats, and there is no longer an adequate amount of food or shelter for bees. This would be cruelly ironic, since by clearing land for farming, crops that are planted will not be pollinated.
There also may be a variety of natural causes as well. The varroa mite, an invasive parasite of honey bees, sucks the blood from adult drones and larvae, weakening the bees and shortening their lives. Introduced to Europe in the 1970’s and the United States in the late 1980’s, the nonnative mite has caused massive bee deaths, as local bees have no natural defenses. Diseases such as Israeli acute paralysis virus and the gut parasite Nosema could have also contributed to hive die offs. However, an increasingly likely explanation is that a combination of multiple human related factors have caused immune-suppressing stress on bees across the world, making them more susceptible to natural aliments.
That’s a bummer for bees, but why are they so important?
Bees and flowering plants have been working together for the last 100 million years. The bees are attracted to a flower by its nectar, a sugar rich food source which the bees bring back to their colony to create honey. When a bee lands on a flower to extract the nectar, it gets covered in pollen. Those pollen grains contain the sex cells of the plant. As the bees move from flower to flower, they distribute the pollen, fertilizing the plants, allowing them to reproduce. Over millions of years, bees and flowering plants have changed together so that their adaptations are mutually beneficial. Scientists call this coevolution. It’s been a lucrative partnership and has allowed flowering plants to become the dominant flora on Earth.
But there’s more to the story. Plants are the foundation of almost every single food web. Through photosynthesis they capture the sun’s light energy, combining it with water and carbon dioxide to use as food. When an animal eats a plant, they absorb that food for themselves to use as energy. When another animal eats that animal, the energy moves up the chain again. Without plants, there would be no way to get energy into the ecosystem. If you remove plants, there is no way for the entire ecosystem to get energy, and it collapses.